Heater for hypodermic solutions and the like



Ju1 20,1937. RTHSHMAN 2,087,586

HEATER FOR HYPODERMIC SOLUTIONS AND THE LIKE Filed Feb. 28, 1935 INVENTOR. 3 (I ATTORNEY Patented July 20, 1937 UNITED STATES PATENT OFFICE HEATER FOR HYPODERMIC SOLUTIONS AND THE LIKE 11 Claims.

This invention relates to a heating device and more particularly to a thermostatically controlled heater for flowing liquids, such as hypodermic solutions and the like.

An object of the invention is to provide a sensitive temperature control for liquids of the above type.

Another object is to maintain a hypodermic solution at a substantially constant temperature during the injection period.

Another object is to control the temperature of a hypodermic solution at the point of injection, regardless of any variations in temperature of the ampoule or container.

A further object is to provide a simple, convenient and dependable means to accomplish the above purposes.

Although the novel features which are believed to be characteristic of this invention will be pointed out more particularly in the claims appended hereto, the invention itself, as to its objects and advantages and the manner of its operation, will be better understood by referring to the following description taken in connection with the accompanying drawing in which one embodiment thereof is disclosed for purposes of illustration.

In the drawing,

Figure 1 is a side elevation showing the heater assembled with an ampoule and an injection needle;

Figure 2 is a broken side elevation of the heater;

Figure 3 is a top plan view thereof; and

Figure 4.- is a side elevation of the heater showing the flexible tubes arranged for sterilization.

In the following description and in the claims, various details will be identified by specific names for convenience, but they are intended to be as generic in their application as the art will permit.

Referring to the drawing, there is shown in Figure l a heater Ill which is mounted in a spring clamp II slidably secured to a suitable stand 12 and connected by a flexible tube I3 to a container for hypodermic solutions, such as an ampoule M, which is likewise supported from the stand 12, as by a hook l5 engaging the stem iii of the ampoule. The heater H] is also connected by a flexible tube 20 to a thermometer well 2i carrying a thermometer 22. The thermometer well 2| is connected by a flexible tube 23 to an injection device, such as an injection needle 24.

The ampoule M may be of the type disclosed in 55, the patent to Blaivas No. 1,905,362, dated April 25, 1933, in which the stem [6 provides a vent for the liquid within the ampoule and forms a physical support to engage the hook [5 of the stand. The lower portion of the ampoule is elongated to form a stem adapted to receive the tube it for discharge purposes. It is to be understood, however, that this type of ampoule is referred to only for purposes of illustration and that any other suitable container for hypodermic solutions may be employed. It is also to be understood that the thermometer well 2i may be omitted, provided it is not necessary to ascertain the temperature during the injection period, in which case the tube 20 is connected directly to the injection needle 25 so as to discharge the liquid directly from the heater Ill thereto. A suitable clip 26 may also be provided to regulate the flow of liquid from the ampoule to the injection needle.

The heater H] is shown more in detail in Figures 2 and 3 as comprising a container or jar 36, preferably of glass or the like, having a plurality of fins 3| formed as a helix on the outer surface thereof and providing channels 32 therebetween adapted to receive the coiled tubes l3 and 20 for the purposes to be described. A plurality of spring clips 33 are positioned in said channels 32 at spaced points so as to grip the coiled tubes for holding the same in position. Said clips 33 may be mounted by wires 34 extending around the container and located in suitable recesses 35 formed therein.

A pipe 36, preferably formed of glass, is mounted in thermal contact with the liquid within the container 30. This pipe may be of any convenient shape, such as an open loop, as shown in Figure 2, and may be supported in any convenient manner. It may, for example, be sealed to the walls of the container 33 and may extend therethrough to form nipples 38 and 39 to which the flexible tubes [3 and 20, respectively, may be connected. The arrangement is such that the hypodermic solution may be passed through the pipe 36 and may be heated in its passage therethrough by heat transfer from the liquid within the container 36. Obviously, the pipe 36 may be of any convenient length which is adapted to give the required heat transfer. The pipe may, forexample, include a coil of one or more turns, if desired.

The container 30 is provided with a cover 40, preferably of insulating material such as bakelite or the like, which carries the heating unit and thermostatic control device, to be described. The cover 40 may be secured to the container 30 in any convenient manner, as by a partial thread 4| formed on the container and cooperating with lugs 52 formed on the cover. A suitable sealing ring 43 may also be used to effect a tight seal.

The cover 49 carries a housing 50 which may be secured thereto, as by a pin i and a nut 52. A tube 53 may be mounted on the housing 50 and extends through the top 40 into the container 35. A second tube 5 5 is rotatably mounted within the tube 53 and carries at its upper end a worm gear 55, which may be secured thereto as by a screw 55, and is adapted to be rotated by a cooperating Worm 51, mounted on a rod 58 and carrying control knob 59. The control knob 59 may be provided with a suitable index 59' graduated to indicate the condition of adjustment of the tube 54 and the associated elements.

The tube 54 carries at its lower end a block 69 to which is secured one end of a bi-metallic helical thermostat iii, the other end of which is secured to a rod 52 extending through the helical thermostat 5i and through the tube 54 and carrying at its upper end a block 55 of insulating material, which may be secured thereto as by a screw 55. The block 65 carries a contact arm 5'! having secured thereto a contact 68 which is adapted to engage a stationary contact 59 connected to a binding post 75. Electrical connection may be made to the contact arm 5i from a second binding post l3 by means of a flexible conductor 14 having a loop adapted to provide the necessary flexibility. Bolts it may extend through the block 55 to secure: and make electrical connection between the flexible conductor 74 and the contact arm 61.

It is to be understood that the binding posts 19 and i9 and the contact elements above describe-d are supported by and suitably insulated from the housing 59. It is also to be understood that the type and construction of the switch and thermostat may be varied as desired. A specific form has been shown merely as an illustration of a particular embodiment of the invention.

A condenser 89 may also be mounted on the cover 49 and may be provided with a pair of terminals 3i which are connected to the binding posts it and l3. The condenser may be of ap propriate size to prevent sparking at the contacts 65 and 69 when the contacts are separated during normal operation.

The cover W may also carry a connector block 90 having an electrical heating unit 9! depending therefrom and extending through the cover into the liquid within the container 39. The unit 9! b may be connected to the binding posts 10 and 13,

as by leads 92, and may be connected to suitable spring fingers 93 which are adapted to make contact with the prongs 96 of a standard plug connector 95, the connection being such that the contacts 68 and 69 control the flow of current through the heating unit 9|.

In order to prevent accidental insertion of the connector 5:5 when the cover 49 is not mounted in position on the container 30, a lever Hill is provided which is pivoted to the connector block 99, as at llll and is bent at its upper end to form a pin 92 which is caused by a spring N13 to project forwardly from the connector block 90 so as to prevent the connector 95 from being inserted therein. The lever Hill is provided at its lower end with an arm it which is adapted to contact with the outer surfaces of the container 39 so as to cause movement of the lever I00 for retracting the pin I82 when the cover 40 is in position on the container 39 and thereby to permit the connector 95 to be attached to the connector block 90. The cover 40 may also be provided with a filler opening H0, closed by a cap I l l and a gasket I i2. A vent I [4 may be provided in the container 30 and may have a nipple H5 associated therewith to facilitate attachment of a flexible tube for the purpose to be described.

In operation, the container 30 is filled with a suitable heat-transfer liquid, such as water. The cover 48 is locked in position thereon and suitable electrical connection is made by the connector 95. The current flowing through the heating unit 9! serves to heat the liquid within the container and actuates the thermostat 6! in accordance with the temperature thereof. Suitable adjustment is made of the thermostat 6 l, as by manipulation of the knob 59, to cause the thermostat to separate the contacts 68 and 69 when the proper temperature has been reached. Thereafter, the thermostat serves to maintain the liquid at about said temperature. The required temperature of the liquid will depend upon the initial temperature and rate of flow of the solution to be heated within the pipe 36 and the eifective length of said pipe in heat-transfer relationship with the liq-- uid. It is obvious that by suitable adjustment of the knob 59 the heat may be so controlled that the solution can be discharged from the heater at any predetermined temperature.

As applied to the heating of a hypodermic solution, the heater NJ may be mounted upon the stand 12, as illustrated in Figure l, and the pipe 35 thereof may be connected to the flexible tubes [3 and 20, leading respectively to the ampoule l4 and the thermometer well 2! or to the injection needle 24. Using a given hypodermic solution, experience will determine the initial setting of the knob 59 to produce the desired temperature at the needle 24. While the injection is being carried out, the thermometer 22 may be noted and any variations in temperature may be compensated for by suitable adjustment of the knob 59. It is obvious that the temperature of the hypodermic solution may thus be maintained substantially constant during the entire period of injection and may be accurately controlled at the point of injection. If a temperature indication is not required in any particular case, the thermometer well 2! may be omitted and the tube may be connected directly to the injection needle 24, the device operating otherwise as above indicated.

The pipe 36 and the flexible tubes l3 and 20 may be sterilized prior to use by the method illustrated in Figure 4. For this purpose the tubes I3 and 20 are disconnected from the ampoule and the thermometer well 2|, respectively, and are wrapped around the container 30 within the grooves 32 which are provided for this purpose, the clips 33 securing the tubes in position. The free end of tube [3 may be connected to the nip ple H5, while the free end of the tube may be left open. Heating current is then applied and suitable adjustment is made of the thermostat 6! to permit the liquid to boil, thus producing steam which passes from the vent I I4 through the nipple I I5, through the tube l3, thence through the pipe 36, and through the flexible tube 20 from which it is discharged. Steam may be applied for a suificient length of time for sterilization purposes.

It is to be noted that the process and apparatus above set forth provide a dependable, practical and eflicient means for accomplishing the purposes specified. The device maintains the temperature of flowing liquids at predetermined values without requiring frequent or skilled manipulation. This feature is of special importance in connection with hypodermic solutions or the like which are to be applied to body tissues, particularly if the solutions are being injected over an extended period of time. The invention is not limited to such use, however.

It is to be understoodthat the details above described constitute only a single embodiment of the mechanical features of the invention. Various changes may be made as desired in the thermostatic control and in the heating unit, as well as in the manner of mounting the same. The pipe 36 may also be variously located or mounted, as from the cover Ml, if desired. The fins 3i may be omitted if the flexible tubes are otherwise supported for the sterilization step or if sterilization is otherwise effected.

A specific embodiment of the invention has been shown and described for purposes of illustration only. Various changes and modifications may be made therein and it may be applied to various other uses as will be readily apparent to a person skilled in the art. The invention is accordingly to be limited only in accordance with the following claims when interpreted in view of the prior art.

I claim:

1. A heater for hypodermic solutions and the like adapted to be slidably secured to a stand and comprising a container adapted to receive a liquid, a means to pass the solution to be heated in heat-transfer relationship with said liquid, a cover detachably mounted on said container, an electrical heating unit and a thermostat carried by said cover in heat-transfer relationship with said liquid, and a means actuated by said thermostat to control the energization of said heating unit so as to maintain said liquid at a predetermined temperature.

2. A heater for hypodermic solutions and the like comprising a container adapted to receive a liquid, a pipe adapted to carry the solution to be heated, said pipe passing through and being sealed to the walls of said container and extending into heat-transfer relationship with the liquid therein, a cover detachably mounted on said container, an electrical heating unit and a thermostatically controlled switch mounted on said cover, said heating unit extending into said container and being adapted to control the ternperature of said liquid, said thermostatically controlled switch being adapted to control the energization of said heating unit in accordance with the temperature of said liquid.

3. A heater for hypodermic solutions and the like adapted to be slidably secured to a stand and comprising a container adapted to receive a liquid, a pipe mounted in heat-transfer relationship with said liquid and adapted to carry the solution to be heated, a cover detachably mounted on said container and thermally responsive heatsupply means carried by said cover, said means comprising an adjustable thermostat, an electrical heating unit, a switch operable by said thermostat to control the energization of said heating unit, and a condenser connected across said switch to prevent sparking thereof.

4. A heater for hypodermic solutions and the like adapted to be slidably secured to a stand and comprising a container adapted to receive a liquid, a pipe mounted in heat-transfer relationship with said liquid and adapted to carry the solution to be heated, a cover detachably mounted on said container and thermally responsive heatsupply means carried by said cover, said means comprising an adjustable thermostat, an electrical heating unit, a switch operable by said thermostat to control the energization of said heating unit, a condenser connected across said switch to prevent sparking thereof, a connector block adapted to receive a detachable connector, and means associated with said connector block to prevent attachment of said connector except when the cover is in position on the container.

5. A heater for hypodermic solutions and the like comprising a container adapted to receive a liquid, a pipe mounted in heat-transfer relationship with said liquid and adapted to carry the solution to be heated, a cover mounted on said container and thermally responsive heat-supply means carried by said cover, said means comprising an adjustable thermostat, an electrical heating unit, a switch operable by said thermostat to control the energization of said heating unit, a condenser connected across said switch to prevent sparking thereof, a connector block adapted to receive a detachable connector, means associated with said connector block to prevent attachment of said connector except when the cover is in position on the container, said last means comprising a member normally extending from said connector block to prevent adjustment of said connector, and a lever engaged by the container to retract said member when said cover is positioned thereon.

6. A heater for hypodermic solutions and the like adapted to be slidably secured to a stand and comprising a container adapted to receive a liquid, means to maintain said liquid at a predetermined temperature, a pipe extending through said liquid in heat-transfer relationship therewith and adapted to receive the solution to be heated, a vent associated with said container above the liquid level, said vent communicating with a nipple adapted to receive a flexible tube, whereby connections may be made to pass vapor from said vent through said first pipe for sterilization purposes.

'7. In combination with a source of hypodermic solution and an injection device, a heater adapted to be slidably secured to a stand and comprising a container adapted to receive a liquid, means to control the temperature of said liquid, a pipe in heat-transfer relationship with said liquid, means connecting said pipe to said source and to said injection device whereby said solution is passed through said pipe, is heated therein and discharged to said injection device at a predetermined temperature, and means associated with said heater to vary the temperature range thereof.

8. In combination with a source of hypodermic solution and an injection device, a heater adapted to be slidably secured to a stand and comprising a container adapted to receive a liquid, means to pass the solution from said source in heat-transfer relationship with said liquid and thence to said injection device whereby said solution is applied to said injection device at a predetermined temperature, means to indicate the temperature of the liquid applied to said injection device, and means to regulate the temperature of the liquid in said heater whereby the temperature of the discharged solution may be maintained substantially constant.

9. A heater for hypodermic solutions adapted to be slidably secured to a stand and comprising a container adapted to receive a liquid, a pipe in heat-transfer relationship with said liquid, and means to maintain said liquid at predetermined temperatures, said container having a fluted surface comprising helical channels adapted to receive a flexible tube, and means to secure said flexible tube therein.

10. A heater for hypodermic solutions and the like adapted to be slidably secured to a stand and comprising a container adapted to receive a liquid, a pipe adapted to carry the solution to be heated, said pipe passing through the walls of said container and extending in heat-transfer relation ship with the liquid therein, a cover detachably mounted on said container, an electrical heating unit and a thermostatically controlled switch mounted on said cover, said heating unit extending into said container and being adapted to control the temperature of said liquid, said thermostatically controlled switch being adapted to control the energization of said heating unit in accordance with the temperature of said liquid,

11. A heater for hypodermic solutions and the like comprising a container adapted to receive a liquid, a pipe mounted in heat-transfer relationship with said liquid and adapted to carry the solution to be heated, a cover detachably mounted on said container and thermally responsive heatsupply means carried by said cover, said means comprising an adjustable thermostat, an electrical heating unit, a switch operable by said thermostat to control the energization of said heating unit, a connector block adapted to receive a detachable connector, and means associated with said connector block to prevent attachment of said connector block except when the cover is in position on the container.

PAUL TISHMAN. 

